Emerson Rosemount 702 Quick Start Manual page 32

Quick Start Guide
Figure 5-17:
A. Measured
B. Reported
5.8.3 Latching warnings
WARNING!
When state latching is enabled, the discrete variable reported to the system
will represent the latched value which may not be the actual state value
measured by the Rosemount 702 Transmitter
WARNING!
Ensure that the state latch time value is long enough for the value to be
reported throughout the entire system to guarantee the state transition is
not missed. After configuring discrete latching function, check for proper
operation at the system level to ensure the desired state transitions are
captured as desired.
5.8.4 System Verification
After installation of the 702DX52 for plunger arrival one must verify
functionality.
• Verify the sensor: To do so, pass a ferrous object (ex. Wrench) past the
cyclops sensor to simulate an arrival. Verify via the LCD screen and/or
field communicator that channel 1 indicates a state change. If a state
change is seen, sensor wiring is correct; if nothing is seen, please go back
through the installation steps and confirm that everything has been done
accordingly.
• Verify System integration: It is important to verify the latch time is
configured correctly. The default latch period is set to one minute. Verify
the host system can detect the arrival event by moving a ferrous metal
object (ex. Wrench) past the arrival sensor. The signal should be passed
from the device, through the Wireless Gateway and detected at the final
host application (ex. PLC, Modbus/OPC, etc.). If nothing is seen, confirm
the latch time is appropriate considering the full system scan cycle.
32
Latch Hold Timer Restarts
A
B
Rosemount 702 Wireless Discrete Transmitter
April 2018